Sure. I think at one time tethering was not a big deal to the cell companies. But now they hate it so much I think they all will drop your service if they find out you're doing it without paying extra for it. Though I guess that can make it even more fun ;)
I don’t know...my Verizon guy told me specifically I could do it with my Blackberry.
He actually talked me out of the MiFi by saying that!